Conventional devices performing warming therapy apply heat to the entire body of a patient situated on a mattress. Such devices are often used, for example, to warm infants immediately after they are born.
One such conventional warming therapy device is shown in FIG. 1 of the present application. In particular, FIG. 1 shows a warming device 100, which includes a patient surface or mattress 101, and a radiant heat source 105. The radiant heat source 105 provides energy, in the form of infrared (IR) radiation 104, onto the entire mattress 101, and any patient which is situated thereon. However, most patients do not occupy the entirety of the mattress 101, and indeed, most patients (particularly infant patients), only occupy a small portion of the mattress 101. As a result, most of the radiation 104 emitted from the heating source 105 is wasted, resulting in energy and power inefficiencies, and increased heating of the area surrounding the warming device 100, and the room in which it is situated. Particularly, the unnecessary heating caused by the warming device 100 imposes an additional load on the climate control system. In other words, the excess warming requires the temperature control system (e.g., HVAC system controlled by a thermostat) in the surrounding room to work harder to maintain a constant and even temperature for the other occupants. Excess heating also affects the healthcare workers who are in close proximity to the warming device, leading to less comfortable working conditions. Wasted radiated energy also leads to excessive electric energy use by the warming device 100, which increases electric power consumption by the health care provider (e.g., hospital), and shortens the time the device can operate on battery power, such as during transport or power failure.
Additional drawbacks of conventional warming devices (such as shown in FIG. 1), include the use of contact-type sensors. Contact sensors, such as thermometers, often include lead wires which are coupled to the patient at one end (i.e., by medical tape or other adhesives), and to a controller unit of the warming device at the other end. As will be appreciated by those skilled in the art, such lead wires often inhibit patient movement, and/or may lead to sensor dislodgement or displacement by such movement. In addition, contact-type sensors pose a significant risk of injury to infants in particular, especially newborn or premature infants whose skin is very fragile and susceptible to damage (and thus not suitable for the use of adhesives, such as medical tape). For example, U.S. Pat. No. 7,008,371, the disclosure of which is hereby incorporated by reference into the present application, teaches a warming apparatus which includes a patient temperature probe 202 which is coupled to directly the patient. Another drawback of conventional warming devices which use contact-type sensors is that they are only useful for sensing those areas of the patient's body to which they are connected. As a result, other non-contacted areas of the patient may not receive the proper amount of warming therapy. A proposed solution to this challenge is the utilization of patient sensors which are not directly coupled to the patient's body, and/or which do not require adhesives, such as medical tape.
Accordingly, there is presently a need for a warming device that improves upon the energy and power inefficiencies of conventional devices, while eliminating the drawbacks associated with conventional contact-type sensors. It is also desirable to have a warming device that accurately senses all areas of a patient's body, and in response, selectively provides the appropriate amount of warming therapy to such areas.